Apparatus for wrapping pipe with multiple strips

ABSTRACT

A method and apparatus for wrapping pipe, of the type used in gas pipe lines for example, with multiple strips of metal strapping. The pipe is mounted on a pair of chucks which fit into the open ends of the pipe to rotate the pipe while multiple spools of metal strapping are moved axially along the pipe. The ends of the multiple strips of strapping are initially clamped to a dummy mandrel having the same outside diameter as the pipe, and this mandrel is rotated along with the pipe so that the multiple strips of strapping are wound helically around the mandrel and the pipe as the spools of strapping are traversed along the length of the pipe. At the terminating end of the pipe, the wrapping of the multiple strips of strapping is continued on to a second dummy mandrel having the same outside diameter as the pipe, and the strapping is then clamped and cut on the second dummy mandrel. A pair of cutting discs are provided for cutting off the metal strapping flush with the ends of the pipe, and a pair of clamping ring locators are provided for positioning clamping rings adjacent the opposite ends of the pipe. The chucks which hold and rotate the pipe comprise expanding mandrels for expanding the pipe and the wrapping outwardly against the clamping ring so that the wrapping is clamped firmly between the clamping ring and the pipe at both ends of the pipe.

United States Patent [191 Fencl et al.

[111 3,823,883 [451 July 16,1974

1 1 APPARATUS FOR WRAPPING PIPE WITH MULTIPLE STRIPS [75.] Inventors: Vernon R. Fencl, Northbrook;

Albert Roze, Chicago; Edward M. Naureckas, Gumee, all of Ill.

[73] Assignee: Grotnes Machine Works, Inc., Chicago, 111.

[22] Filed: Feb. 22, 1972 [2]] Appl. No.: 227,995

[52] U.S. Cl 242/7.23, 29/208 D, 29/452, 83/924, 242/702 [51] Int. Cl B65h 81/08, B2-1f 3/04 [58] Field of Search 242/723, 7.21, 7.22; 156/425, 446, 185, 184, 187, 188, 193, 267;

Primary ExaminerBilly S. Taylor Attorney, Agent, or Firm-Wolfe, Hubbard, Leydig,

Voit & Osann, Ltd.

57 ABSTRACT A method and apparatus for wrapping pipe, of the type used in gaspipe lines for example, with multiple strips of metal strapping. The pipe is mounted on a pair of chucks which fit into the open ends of the pipe to rotate the pipewhile multiple spools of metal strapping are moved axially along the pipe. The ends of the multiple strips of strapping are initially clamped to a dummy mandrel having the same outside diameter as the pipe, and this mandrel is rotated along with the pipe so that the multiple strips of strapping are wound helically around the mandrel and the pipe as the spools of strapping are traversed along the length of the pipe. At the terminating end of the pipe, the wrapping of the multiple strips of strapping is continued on to a second dummy mandrel having the same outside.

diameter as the pipe, and the strapping is then clamped and cut on the second dummy mandrel. A pair of cutting discs are provided for cutting off the metal strapping flush with the ends of the pipe, and a pair of clamping ring locators are provided for positioning clamping rings adjacent the opposite ends of the pipe. The chucks which hold and rotate the pipe comprise expanding mandrels for expanding the pipe and the wrapping outwardly against the clamping ring so that the wrapping is clamped firmly between the I clamping ring and the pipe at both ends of the pipe.

3 Claims, 9 Drawing Figures I ken lines;

APPARATUS FOR WRAPPING PIPE WITH MULTIPLE STRIPS DESCRIPTION OF THE INVENTION The present invention relates generally to the fabrication of high strength composite pipe of the type that has a basic solid core pipe wrapped with a high strength wrapping material. v

Pipe that is wrapped with a high strength material such as metal strapping or wire provides both technical and economic advantages in terms of higher resistance tiple strips of strapping to be wound on the pipe simultaneously.

A further object of the invention is to provide an improved method and apparatus of the foregoing type that automatically clamps the strapping to the pipe.

Yet another object of the invention is to provide such an improved method and apparatus that continues the wrapping beyond the ends of the pipe, and automatically cuts the strapping flush with the ends of the pipe.

A still further object of the invention is to provide apparatus of the typedescribed above that is of rugged construction and efficient to operate.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIG. 1 is a perspective view of a pipe wrapping machine embodying the invention, with a pipe inserted in the machine to be wrapped;

FIG. 2 is a sectiontaken along line 22 .in FlG. 1;

FIG. 3 is-a section taken along line 3-3 in FIG. 1, with a portion of strapping carriage broken away to show the internal structure;

FIG. 4 is a section taken along line 44'in FIG. 1, I

with the axially movable head assembly in its most advanced position;

FIG. 5 is an enlarged perspective of that portion of the machine of FIG. 1 where the pipe wrapping is initiated and showing the beginning of a-wrapping and the end portion of apipe inserted in the machine to be wrapped; I

FIG. 6 is an enlarged fragmentary section taken through the pipe and its wrapping while in the machine ofFIG. 1; I

FIG. 7'is an enlarged perspective of the axially movable head assembly of the machine of FIG. 1, with portions thereof shown in a more advanced position in bro- I While the invention is susceptible of various modifications and alternative forms, certain specific embodiments thereof are shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but, on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as expressed in the appended claims.

Turning now to the drawings, and referring first to FIG. 1, there is shown a pipe wrapping apparatus adapted to hold a pipe 10 to be wrapped in a horizontal position between a stationary head assembly 11 and a horizontally movable head assembly 12. The two head assemblies 11 and 12 carry a pair of chucks in the form of expanding mandrels 13 and 14, respectively,-

adapted to fit into the open ends of the pipe 10. To permit adjustment of the distance between the two mandrels 1'3 and 14 for mounting different lengths of pipe 10 on the mandrels, and for removing the pipe therefrom after ithas been wrapped, the head 12 is mounted for longitudinal movement on a bed 15 for longitudinal movement in the direction of the axis of the pipe 10. The power means for advancing and retracting the movable head 12 relative to the stationary head 11 is illustrated as a hydraulic cylinder'16, but it will be understood that any conventional power means may be used for this purpose. The expanding mandrels l3 and 14 are also conventional and may, for example, be of the type described in U.S. Pat. No. 3,583,200 to Cvijanovic. It will be understood that expanding mandrels of this type may be actuated at any selected time to expand the mandrel outwardly in the radial direction so as to apply predetermined radial forces against themside walls of the pipe. These radial forces may be adjusted to merely provide a gripping actionbetween the engaging surfaces of the mandrel and pipe, or they may be increased to actually expand the pipe as well as any wrappings and clamping rings disposed around the pipe) outwardly to increase the inside diameter of the pipe- V In accordance with one aspect of the present invention, the pipe wrapping machine includes a carriage mounted for axial movement along the pipe 10, and carrying a plurality of rotatable spools of metal strapping. The strapping is withdrawn from the spools by rotation of the pipe while the strapping carriage is simulpair of track members 21 and 22 extending parallel to each other and to the pipe 10. A pair of spaced rollers 23 and 24 journaled on the outboard side of the carriage ride on the upper and lower surfaces, respec-' tively, of thetrack member 22, while a third roller25 journaled on the inboard side of the carriage 20 rides on the top surface of the track member 21. To move the carriage 20 back and forth along the track members 21 and 22, a power-driven screw 26 is threaded through a projection 27 on the bottom of the carriage 20. The driven system for turning the screw 26 is contained within the stationary head assembly 11, and includes a motor 17- driving the screw 26 via a speed re- I I ducer 18'(FIG. 2).

The metal strapping to be wrapped around the pipe is contained in four spools 28, 29, 30, and 31 rotatably mounted on one side of the carriage 20. These four spools are staggered with respect to one another in the direction of. the axis of the pipe 10 so that the ad jacent strips of strapping 28a, 29a, 30a, and 31a withdrawn from the spools only partially overlap each other. The four overlapping strips of strapping are passed through the nips of a pair of guide rollers 32 and 33, and are withdrawn from the four spools by rotation of the pipe 10 and the dummy mandrels'associated therewith (to be described below), The pipe 10 is rotated by rotation of the mandrel 13 which in turn is rotated by a conventional drive motor mounted within the head assembly 11. More specifically, the mandrel 13 is rotated by the same drive motor 17 that drives the carriage-traversing screw 26; as shown in FIG. 2, the motor 17 is connected to the mandrel 13 via a clutch and brake assembly 34 to permit the mandrel 13 to be disconnected from the motor 17 during the return traverse of the carriage 20. During the advancing traverse I of the carriage 20, the use of the common motor '17 provides the desired synchronization of the carriage movement with rotation of the pipe 10.

In keeping with the invention, the four spools 28-31 of metal strapping are oriented at an acute angle to the axis of the pipe 10 so that the four strips of strapping are fed to the pipe at the same acute angle. Consequently, the strapping is wound helically on the pipe as the pipe is rotated'during the traversing movement of the carriage along the length of the pipe. The multiple strips of strapping may be wound on the pipe in a number of different patterns, but one particularly useful pattern is shown in FIG. 6 and is described in the assignees copending U.S. Pat. application Ser. No. 227,822, filed Feb. 22, 1972, entitled Method of Wrapping Pipe with Multiple Strips of Metal Strapping and Resulting Product," filed concurrently herewith. Briefly described, each strip of metal strapping 28a, 29a, 30a and 31a wrapped around the pipe 10 overlaps each adjacent strip of strapping by an amount suchthat the abutting edges of successive winding'of the strip in each layer are axially spaced from the abutting edges of successive windings of the strips in all other layers.

In accordance with one'of the important aspects of the present invention, a pair of dummy mandrels are disposed adjacent the pipe chucks and have outside diameters substantially the same as that of the pipe 10 so that the wound strapping may continue .beyond the ends of the pipe onto the dummy mandrels. Thus, in the illustrative machine a pair of dummy mandrels 40 and 41 are mounted between the mandrels l3 and 14 and their respective head assemblies 11 and 12. The dummy mandrels 40 and 41 are fixed to the shafts that rotate the mandrels 13 and 14 so that the dummy mandrels are rotated along with the pipe 10 when the mandrel 13 is rotated. The dummy mandrels 40 and 41 are positioned so that when the pipe 10 is mounted on the mandrels 13 and 14, the ends of the pipe 10 abut the two corresponding ends of the dummy mandrels 40 and 41 so that the outside surfaces of the pipe 10 and the two mandrels 40 and 41 form a substantially continuouscylindrical surface. Thestrapping carriage 20 is shown in its starting position in FIG. 1, so that the wrapping operation starts at the dummy mandrel 41, proceeds along the length of the pipe 10, and terminates on the dummy mandrel 40.

More specifically, the strip of metal strapping in each of the four layers overlaps the strip of metal strapping each adjacent layer by (1 A) or ofthe width of each strip of strapping. This fraction of overlap can be expressed generally as (l-l/n) where n is the number of layers of metal strapping wound on the pipe. Because of the degree of overlap, it can be seen that the helical joint formed by the abutting edges of each strip of metal strapping is not aligned with, and indeed never intersects, the joints of any of the other strips. Consequently, a radial line projected through the multi-layer wrapping at any given point can never pass through 1 more than one joint or, conversely, can never pass through less than three-layers of wrapping. With this particular multi-layer wrapping pattern, the additional strength imparted by thereinforcing wrapping is substantially uniform along the entire length of the pipe. and around the entire-circumference of the pipe. Thus, there are not any weak areas in the wrapping where the wrapped pipe is more susceptible to fracture than in other areas.

As one particular feature of the invention, the carriage 20 includes means for automatically feeding the leading ends of the multiple strips of strapping into a cavity formed in the outer surface of the mandrel 41,

and clamping means are provided within the cavity of the mandrel 41 to receive and clamp the leading ends of the metal straps. Thus, as shown most clearly in FIG. 3, the carriage 20 includes a pair of clamping jaws 42 and 43 whichare opened and closed by means of a hydraulic actuating cylinder 44. When it is desired to initiate a wrapping operation, the cylinder 44 is actuated to close the clamping jaws 42 and 43, thereby clamping all four strips of metal strapping between the jaws with the free ends of the strapping extending beyond. the jaws 42 and 43' toward the mandrel 41. After the clamping jaws 42 and 43 have been closed, a second hydraulic cylinder 45 is advanced to pivot the entire clamping assembly about its pivot point 46, toward the dummy mandrel 4]. As the clamping jaws 42 and 43 approach the dummy mandrel 41, the leading ends of the four strips of metal strapping are advanced into a cavity 47 in the mandrel 41 and gripped by a hydrauli-' cally actuated clamping assembly 48 contained therein. This completes the feeding operation, and the drive motor 17 is then energized to rotate the pipe 10, along with the dummy mandrels 40 and 41, while the carriage 20 begins its traversing movement along the tracks 21 and 22. The four strips of metal strapping are thus withdrawn from the spools 28-31 and wound helically around the dummy, mandrel 41, then the pipe 10, and .finally the. dummy mandrel 40. I

When the carriage 20 reaches the end of its traversing movement, a clamping and cutoff tool 50 (FIG. 4) is advanced by a'hydraulic cylinder 51, with thetool 5 0 v I fitting into a complementally formed cavity 52 in the outer surface of the dummy mandrel 40; The leading end of the tool 50 is rounded so as to deform the metal strapping into the cavity 51 to provide a clamping action, while the top of the tool. 50 forms a cutting edge invention, a pair of clamping ring locators 70 and 71 are provided for receiving and holding clamping rings for holding the wrapped strapping on the pipe 10. A clamping ring 73 is disposed concentrically within each locator 70 and 71 and held therein by tightening the locator to reduce the inside diameter until it clamps the clamping ring 73 firmly in place. A number of different types of clamping rings may beemployed in the illustrative apparatus, but one particularly useful clamping ring is shown in FIG. 8 and is described in the assignees copending U.S. Pat. application Ser. No. 227,797 filed, Feb. 22, 1972 entitled Clamp and Reinforcing Ring For Pipe Wrapping, filed concurrently herewith. Briefly described, the clamping ring 73 comprises a unitary metal annulus forming a pair of annular peripheral sections 74 and 75 and an annular center section 76 curved outwardly away from the wrapped pipe to form a concave inner surface 77. The ring engages the surface of the wrapped pipe on both sides of the concave surface 77 so that when the pipe 10 is expanded in the radial direction, the center section 76 of the ring is deformed to increase the radius of the curvature thereof, thereby creating a spring force pressing inwardly against the wrapped pipe in the radial direction.

That is, the radial expansion of thewrapped pipe deforms the bowed center section 76 from its original configuration, and the tendency of the deformed center section to return to its original configuration produces a radial biasing force applied inwardly against .the wrapped pipe.

Both peripheral sections 74 and 75 of the illustrative ring are bent outwardly away from the wrapped pipe at a slight angle so that the inside diameters of the peripheries of the ring are greater than the outside diameter of the wrapped pipe, thereby facilitating the fitting of the ring-onto the end of the pipe. The flared periphery also facilitates sliding of the clamping ring 73 axially over the surface of the wrapped pipe without catching on the edges of the successive windings of the outermost layer of metal strapping.

Each locator is movable-axially along the pipe on the bed for locating the clamping ringfnear the end of the wrapped pipe and radially adjacent the corresponding expanding mandrel 13 or 14 so that expansion of the mandrel expands the end of the pipe outwardly against the clamping ring to clamp the strapping onto the. pipe. To advance and retract the locators 70 and 71 along the bed 15, a cylinder rod 78 is passed through.

depending projections 79 and 80 on the bottoms of the locators 70 and 71. The rod 78 is driven by a hydraulic cylinder contained within the stationary head assembly 11. In their starting position, the locators 70 and 7l-surround the respective dummy mandrels 40 and 41. When the wrapping operation is completed, the locators are advanced over the pipe 10 so as to locate the clamping rings 73 immediately adjacent the ends of the pipe, and the expanding mandrels 13 and 14 are then actuated to press radially outwardly against the pipe and thereby expand the ends of the wrappedpipe ,outwardly against the clamping rings 73. This expansion of the end portions of the pipe clamps the metal strapping firmly between the pipe 10 and the clamping rings to hold the strapping in place and at the same time .reinforce the end portions of the pipe. The locators 70 and v 71 are then returned to their starting positions.

As stillanother feature of the present invention, cutting means are located at opposite ends of the pipe 10 for cutting the multiple strips of strapping at both ends of the pipe upon completion of the wrapping operation. Thus, as shown most clearly in FIG. 1, a pair of cutting discs 60 and 61 are mounted on the ends of power driven shafts 62 and 63 directly above the two dummy mandrels 40 and 41, respectively. The shafts 62 and 63 are driven by motors 64 and 65, which in turn are pivotally mounted on brackets 66 and 67 formed on the head assemblies 11 and 12, respectively. When the wrapping operation is completed, the two cutting discs 60 and 61 are loweredby means of hydraulic actuating cylinders'68 and 69, respectively, so that'the cutting edges of the two discs 60 and 61 are lowered into engagement with the metal strapping wrapped around the pipe 10. In order to cut off the strapping flush with the ends of the pipe 10, the cutting discs and 61 are positioned so that when they are lowered they are in alignment with the ends of the pipe 10. The cutting discs 60 and 61 are then rotated simultaneously with rotation of the pipe 10 so asto cut off the metal strapping flush with the ends of the pipe 10. After the cutting operation is-completed, the scrap portions of the strapping remaining on the two dummy mandrels 40 and 41 is peeled off these mandrels and disposed of, so that the equipment is readyfor the next wrapping operation. At

this point, the carriage 20 is returned to its starting po'-' sition, ready to begin the wrapping of the next pipe 10 and the wrapped pipe is ready for removal from the machine.

As can be seen from the foregoing detailed description, this invention provides an improved method and apparatus for wrapping pipe with multiple strips of strapping which are wound onthe pipe simultaneously I in overlapping relationship with each other. The strapping is automatically fed to the first dummy mandrel and clamped thereto, and then automatically wound in helical fashion onto the first dummy mandrel 41, the

pipe 10,.and finally the second dummy mandrel 40.

The wound strapping is then ,cut flush with the ends of the pipe 1 0.by the two cutting discs 60 and 61, after which the strapping remaining on the mandrel 40 is cut by the tool 50.'The remaining scrap'portions of the metal scrapping may then bepeeled off the. two dummy mandrels 40 and 4110 ready the machine for the next wrapping operation. It can be seen that operation of the illustrative machine is simple and efficient, and yet the equipment is of rugged construction so as to provide a long operating life with low maintenance costs. It will be appreciated that the invention is applicable to a wide variety of different wrapping operations, includ ing different numbers of strips of metal strapping which may be wrapped around the pipe different helical patterns, and with different degrees of overlap between adjacent strips of strapping.

We claim as our invention:

1. Apparatus for wrapping pipe withimultiple strips I of high strength metal strapping, said apparatus comprising the combination of a pair of chucks for engaging opposite ends of a length of pipe and rotating the pipe about its axis, a pair of dummy mandrels disposed adjacent said chucks and having outside diameters substantially the same as that of said pipe, carriage means including means for holding a plurality of spools of strips of strapping at both ends of said pipe upon com-' pletion of the wrapping of said pipe and longitudinal cutting means mounted on said carriage means for axially cutting the strapping wrapped on the dummy mandrel at the end of the pipe where the wrapping is stopped.

2. Apparatus as set forth in claim 1 wherein each of said chucks comprises an expanding mandrel.

3. Apparatus for wrapping pipe with multiple strips of high strength metal strapping, said apparatus comprising the combination of pair of chucks for engaging opposite ends of a length of pipe and rotating the pipe about its axis, a pair of dummy mandrels disposed adjacent said chucks and having outside diameters substantially the same as that of said pipe, carriage means including means for holding a plurality of spools of metal strapping and means for simultaneously feeding multiple strips of strapping from said spools onto said dummy mandrels and said pipe with the adjacent strips of strapping overlapping each other, said carriage means also including feeding means for automatically feeding the ends of said multiple strips of strapping to the'dummy mandrel at the end of the pipe where the wrapping is started, said dummy mandrel at the starting end of the pipe including clamping means for clamping the ends of said multiple strips of strapping, and means for moving said carriage means axially along said pipe while said pipe is rotating so as to wrap said multiple strips of strapping around said dummy mandrels and said pipe, and cutting means located at the opposite ends of said pipe for cutting said multiple strips of strapping at both ends of said pipe upon completion of the wrapping of said pipe. 

1. Apparatus for wrapping pipe with multiple strips of high strength metal strapping, said apparatus comprising the combination of a pair of chucks for engaging opposite ends of a length of pipe and rotating the pipe about its axis, a pair of dummy mandrels disposed adjacent said chucks and having outside diameters substantially the same as that of said pipe, carriage means including means for holding a plurality of spools of metal strapping and means for simultaneously feeding multiple strips of strapping from said spools onto said dummy mandrels and said pipe with the adjacent strips of strapping overlapping each other and with the metal strapping at an acute angle to the axis of said pipe, means for moving said carriage means axially along said pipe while said pipe is rotating so as to wrap said multiple strips of strapping around said dummy mandrels and said pipe, transverse cutting means located at the opposite ends of said pipe for cutting said multiple strips of strapping at both ends of said pipe upon completion of the wrapping of said pipe and longitudinal cutting means mounted on said carriage means for axially cutting the strapping wrapped on the dummy mandrel at the end of the pipe where the wrapping is stopped.
 2. Apparatus as set forth in claim 1 wherein each of said chucks comprises an expanding mandrel.
 3. Apparatus for wrapping pipe with multiple strips of high strength metal strapping, said apparatus comprising the combination of pair of chucks for engaging opposite ends of a length of pipe and rotating the pipe about its axis, a pair of dummy mandrels disposed adjacent said chucks and having outside diameters substantially the same as that of said pipe, carriage means including means for holding a plurality of spools of metal strapping and Means for simultaneously feeding multiple strips of strapping from said spools onto said dummy mandrels and said pipe with the adjacent strips of strapping overlapping each other, said carriage means also including feeding means for automatically feeding the ends of said multiple strips of strapping to the dummy mandrel at the end of the pipe where the wrapping is started, said dummy mandrel at the starting end of the pipe including clamping means for clamping the ends of said multiple strips of strapping, and means for moving said carriage means axially along said pipe while said pipe is rotating so as to wrap said multiple strips of strapping around said dummy mandrels and said pipe, and cutting means located at the opposite ends of said pipe for cutting said multiple strips of strapping at both ends of said pipe upon completion of the wrapping of said pipe. 